Endocrinology of ageing

Endocrinology is the study of hormones that allow communication among different organs of the body. This chapter provides an overview of general changes in hormones associated with older age and senescence and under what general circumstances pharmacological replacement of hormones might be warranted. The binding of steroid hormones and thyroid hormone to mitochondrial membrane receptors, which in turn affects the expression of mitochondrial genes and energetics, further blurs the classically limited view of endocrinology taught in our medical schools. The hypothalamic releasing hormones are responsible for maintaining the pulsatility of hormone release, which is essential for optimal hormonal action. The age-related decline in many hormone levels results in difficulties in making the biochemical diagnoses of endocrine disorders. Menopause is the only inevitable and true post-pubertal change in endocrine function that occurs with advancing age. The metabolic syndrome of insulin resistance and obesity can be considered a cause of the accelerated ageing process.